C-clamp



Dec. 16, 1941.

B. J. NEUMANN ET AL -C-CLAMPI Filed Jan, 4, 1940 I. f t 11555:; i D l INVENTORJ A/emmn/zv .bhzzm Z ATTORNEYS Patented Dec. 16, 1941 OFFICE C-CLAMP Bernhard J. Neumann and Millard E. Haller, New York, N. Y.

Application January 4, 1940, Serial No. 312,322

1 Claim.

taken on the lines 22 and 3-3 of Fig. 1; and r Fig. 4 is a front elevation of a portion of the device.

Our improved clamp as illustrated in the drawing comprises a C-shaped frame 2, a clamping screw 4 screw-threaded through an aperture in the end of the upper arm of the frame, a handle 6 for operating the screw, a clamping jaw 8 mounted on the lower or inner end. of the screw, and a clamping jaw ID mounted on the end of the other arm of the frame.

In accordance with the present invention, the jaw 8 is in the form of a disk of inverted frustoconical form having its peripheral surface l2 beveled downwardly and inwardly at an angle of 45 degrees, and its lower end forming a flat clamping surface. The disk jaw 8 is connected with the end of the screw 4 by means of a ball I4 formed on the end of the screw which is received in a socket in the disk. This ball and socket joint permits limited universal movement of the jaw on the end of the screw.

The jaw [0 has a cylindrical boss l6 which rests upon a flattened ledge l8 on the end of the lower arm of the clamp. This boss l6 has a reduced portion in the form of a pin 20 which is in axial alinement with the screw 4 and extends through an aperture in the end of the arm. The jaw Ill is removably held in place by means of a cotter pin '22 which extends through an aperture in the lower end of the pin 20. This connection between the jaw H! and the frame arm permits the jaw to be turned about the axis of the pin 20.

The jaw ii has a V-shaped clamping surface 24 having each side of the V arranged at an angle of 4-5 degrees to the horizontal.

Our improved clamp is particularly adapted for use in welding together pieces of sheet metal to forma right angle corner such as the corner of a metal window frame, consisting of strips of sheet metal 25. In welding such parts the ends of the pieces 26 are positioned in the V of the clamping jaw l0. As this V has its sides arranged at an angle of 45 degrees, the window frame members are accurately positioned with their edges together as shown. When the jaw I0 has thus been applied, upon screwing down the clamping jaw 8, the beveled clamping surface I2 engages the inner sides of the members 26 parallel with the gripping surfaces of the jaw l0 and thus firmly holds these members in proper position. When the two pieces are thus held by the clamp, the frame 2' may be readily swung from side to side as desired out of the way of the worker. Thus the metal pieces are securely and conveniently held for subsequent operations 7 such as welding.

In Figure 4 the clamp is shown holding two pieces 28 of sheet metal in the same plane with their edges abutting at 30. These pieces of metal are firmly clamped over the upper edges of the two sides of the V jaw ID, the flat bottom side of the universally mounted jaw 8 readily adjusting itself to the surface of the two pieces.

Applicants improved C-clamp is found to be much more convenient in use for the purposes mentioned than the C-clamps heretofore commonly used. The clamp may be easily and conveniently applied, a minimum number of clamps are required for a piece of work, and when applied the work may be freely moved from one workman to another without danger of the parts thereof becoming deranged or working loose from the clamp.

As will be evident to those skilled in the art our invention permits various modifications without departing from the spirit thereof or the scope of the appended claim.

What we claim is:

A clamp of the class described comprising a C-frame, a clamping jaw mounted on the end of the lower arm of said frame having a V- shaped clamping surface, a swivel connection between the lower jaw and its supporting frame arm allowing said jaw to turn freely about a vertical axis, a clamping screw screw-threaded through an aperture in the end of the upper arm of the frame having its axis in alinement with the axis of said clamping jaw, and a clamping jaw mounted for universal movement on the lower end of said screw having the lower portion thereof of inverted frusto-conical form whereby when the upper jaw is screwed downwardly it is adapted to enter the V of the lower jaw and the peripheral surface thereof engage and clamp pieces of work against the sides of the clamping surface of the V, the lower end of said upper jaw forming a fiat clamping surface.

BERNARD J. NEUMANN. MILLARD E. HALLER. 

